Due to the constantly progress in the techniques for manufacturing light emitting diode (LED) and the increasing issues in environmental protection and energy saving, people have begun to widely use LED in a variety of illumination applications, such as LED vehicle lights, LED street lamps, LED table lamps, and other LED lamps.
A high-power LED would generate a relatively high amount of heat source during the operation thereof. The generated heat source must be efficiently removed from the product using the LED, lest the heat should accumulate in the product to cause risen temperature particularly at positions near the LED. In a worse condition, the accumulated heat would adversely affect the normal operation and service life of the whole product or some components thereof.
The conventional LED lamp is not provided with a heat dissipation mechanism to remove the heat generated by the LED thereof. When the LED lamp is lightened over a long period of time, the heat generated by the LED would accumulate in the LED lamp and could not be effectively removed therefrom, bringing the LED to burn out due to overheat. To solve the above problem and dissipate the heat accumulated in the LED lamp, there was developed a heat dissipation mechanism for LED lamp as shown in FIG. 1.
Please refer to FIG. 1. The conventional heat dissipation mechanism for LED lamp includes a lamp shade 10, an LED module 11, a heat sink 12, and a lamp holder 14. The lamp shade 10 has a first open end 101 and an opposite second open end 102, and internally defines a hollow receiving space 104 between and communicating with the first and the second open end 101, 102 for receiving the LED module 11 and the heat sink 12 therein.
The heat sink 12 is located between the LED module 11 and the lamp holder 14, and includes a main body 121 and a plurality of radiating fins 123. The main body 121 of the heat sink 12 has a plurality of mounting sections 124 outward extended from an outer periphery of the main body 121, and each of the mounting sections 124 is provided at a free end with a through hole 125. The radiating fins 123 are spaced along the outer periphery of the main body 121 and located between adjacent mounting sections 124. The main body 121 and the radiating fins 123 of the heat sink 12 have one side bearing on the LED module 11, and an opposite side bearing on and connected to the lamp holder 14.
The lamp holder 14 has a main body 141, a plurality of support arms 142, and a third open end 143 facing toward the heat sink 12. The main body 141 of the lamp holder 14 is located in the third open end 143, and the support arms 142 are spaced along and extended from an outer periphery of the main body 141 to the third open end 143 of the lamp holder 14, such that an opening 145 is formed between any two adjacent support arms 142 to communicate with the third open end 143. A mounting hole 146 is formed at each of the joints of the support arms 142 and the third open end 143. A plurality of screws (not shown) are extended through the through holes 125 on the heat sink 12 and the mounting holes 146 on the lamp holder 14 to lock the heat sink 12 to the lamp holder 14, and then, the lamp shade 10 is connected at the second open end 102 to an outer periphery of the lamp holder 14 to complete the conventional heat dissipation mechanism for LED lamp.
When the LED module 11 emits light and generates a high amount of heat, the generated heat is absorbed by the main body 121 and the radiating fins 123 of the heat sink 12, so that the absorbed heat is radiated from the radiating fins 123 to dissipate into ambient air to achieve the effect of removing heat from the LED module 11.
While the conventional heat dissipation mechanism for LED lamp as described with reference to FIG. 1 is able to dissipate the heat generated by the LED module 11 into ambient air, the heat dissipation effect is relatively low because there is only a very small contact surface between the LED module 11 and the main body 121 and the radiating fins 123 of the heat sink 12. Further, the heat sink 12 has poor ability of uniformly spreading heat over a large area. As a result, the heat absorbed by the main body 121 and the radiating fins 123 of the heat sink 12 could not be quickly and uniformly spread to all the radiating fins 123 and radiated into ambient air, and contact areas between the radiating fins 123 and the LED module 11 and the main body 121 of the heat sink 12 tend to have highly raised temperature, bringing the LED module 11 to become locally overheated. This condition would adversely affect an overall illuminance and shorten the service life of the LED lamp. In some worse conditions, the LED module 11 would burn out and become damaged.
In brief, the conventional heat dissipation mechanism for LED lamp has the following disadvantages: (1) providing poor heat dissipation effect; (2) causing lowered illuminance of the LED lamp; and (3) shortening the service life of the LED module.
It is therefore tried by the inventor to develop an improved heat dissipation mechanism for LED lamp, so as to eliminate the drawbacks in the prior art.